FAIRBANKS, Alaska - Visitors to Alaska often marvel at the crisp, clear air. But the truth is, the skies above the Arctic Circle work like a giant lint trap during late winter and early spring, catching all sorts of pollutants swirling around the globe.
In recent weeks, scientists have been going up in government research planes and taking samples of the Arctic haze in hopes of solving a mystery: Are the floating particles accelerating the unprecedented warming going on in the far north?
While carbon dioxide and other greenhouse gases that trap the Earth's heat are believed to be the chief cause of global warming, scientists suspect that airborne particles known as aerosols are also contributing to the Arctic meltdown.
To prove their suspicions, they are analyzing the haze, using mass spectroscopy and other technology to identify what is in it, where it came from and how it interacts with the clouds, the sunlight and the snow cover.
Their air samples have been found to contain dust from Asian deserts, salts that swell up moisture, particles from incomplete burning of organic material from forest and cooking fires, and all manner of nasties emitted by automobile tailpipes, factory smokestacks and power plants.
Collectively, they are a United Nations of pollution. Through chemical analysis, the particles can be traced to their sources throughout Asia, Europe and North America.
'The Arctic is a melting pot for mid-latitude pollution,' said Daniel Jacob, a Harvard scientist taking part in the research. 'We have signatures of just about everything you can imagine flying around in the Arctic.'
The research is being conducted separately by NASA, the Department of Energy and the National Oceanic Atmospheric Administration, and involves about 275 scientists and support staff and five aircraft.
The researchers are building on the work of a University of Alaska Fairbanks atmospheric scientist who arrived 35 years ago. Glenn Shaw took a light meter to Barrow, America's northernmost community, figuring he could document the clearest skies on the globe and perhaps get a mention in a scientific journal.